Percutaneous aortic valve

ABSTRACT

The present invention provides a valve configured for insertion on the proximal and distal sides of a heart valve annulus to replace the heart valve of a patient. The valve comprises a first substantially annular portion adapted to be positioned on a proximal side of the annulus of a patient and a second substantially annular portion adapted to be positioned on a distal side of the annulus of a patient, wherein at least one of the first and second substantially annular portions is movable towards the other portion to a clamped position to clamp around the annulus. The second portion has a flow restricting portion extending therefrom and is movable between a first position to permit the flow of blood and a second position to restrict the flow of blood. In one embodiment, the valve has a suture joining the first and second portions to draw the first and second portions into closer proximity and a cinch member to secure the suture to maintain the first and second portions in the clamped position. In another embodiment, the first and second portions are connected by a first segment which biases the first and second portions toward the clamped position.

This application is a continuation of prior application Ser. No.12/288,620, filed on Oct. 22, 2008 now U.S. Pat. No. 7,803,184, which isa continuation of prior application Ser. No. 11/222,570, filed on Sep.9, 2005, now Pat. No. 7,445,632, which is a continuation of applicationSer. No. 10/429,536, filed on May 5, 2003, now Pat. No. 6,974,476, whichis a national stage application of PCT/US01/43879 filed 11/14/2001 whichclaims priority from provisional application Ser. No. 60/252,187, filedNov. 21, 2000. The entire contents of each of these applications areincorporated herein by reference.

BACKGROUND

1. Technical Field

This application relates to a prosthetic valve and more particularly toa prosthetic valve for minimally invasive replacement of a patient'scardiac valve.

2. Background of Related Art

The aortic and mitral valves are heart valves that open and closeautomatically in response to the pumping of the heart to control bloodflow. The aortic valve is open during ventricular systole, when theheart is in contraction and blood is surged through the aorta andpulmonary artery, and is closed during diastole, when the heart is inrelaxation, dilates and the cavity fills with blood. The aortic valve ispositioned between the left ventricle and ascending aorta and functionsto prevent back flow into the ventricle. The mitral or bicuspid valvecloses the orifice between the left atrium and the left ventricle toprevent back flow into the atrium.

If the aortic valve doesn't close properly after the heart pumps theblood through the valve into the aorta, blood will leak back into theheart. This oxygenated back flow of blood causes the heart to workharder and faster, thereby initially causing chest pain, fatigue, andreduced blood output from the heart, which over time can result incardiomyopathy. Additionally, when the aortic valve is defective for aperiod of time, it oftentimes leads to mitral valve damage because theretrograde inflow of blood applies pressure against the mitral valve,preventing it from closing properly.

There are a variety of causes of heart valve malfunction, many resultingfrom infections or diseases such as congenital heart disease,calcification related to athrosclerosis, and fibrosis. Generally, thereare two types of damaged valves: stenotic valve in which the valve doesnot open fully thereby limiting forward blood flow; and regurgitantvalves in which the valve does not close properly thereby permittingback flow. In either instance, valve malfunction can leads tocardiomyopathy which is a disease of the heart muscle which if leftuntreated can lead to heart failure and death or post stenoticdilatation of the aorta which can lead to aneurysm.

If a defective heart valve cannot be surgically repaired, it may need tobe removed and replaced with a replacement valve. Currently, thesurgical technique for valve replacement is open heart surgery. Thisopen surgery is quite traumatic because it requires a full sternotomy,namely cracking the patient's ribs and creating a chest incisionextending almost along the entire length of the chest. This incision canbe as long as 10-12 inches. Additionally, to perform the valve surgery,the patient's heart is stopped with cardioplegia and the patient isplaced on a heart lung machine requiring withdrawing the blood from thevenous side of the patient through blood flow tubes, transporting theblood to the heart lung machine for oxygenation, and delivering theoxygenated blood to the arterial side of the patient's body throughblood inflow tubes. The problems and risks inherent with the heart lungmachine are well documented. These include the risk of infection, traumato the body as a result of the blood exchange, and the risk of braindamage or stroke. It is also been found that patients who undergo openheart surgery may suffer from permanent neurological lapses.Additionally, in stopping the heart and utilizing the heart lungmachine, the aorta must be cross clamped to cut off the blood flow. Thiscross clamping can dislodge plaque inside the vessel, potentiallysending it through the bloodstream to the brain and causing stroke.Moreover, open heart surgery, being a highly invasive procedure,requires a long patient recovery time. The long patient recovery time,the use of the heart lung machine, and the requirement for additionalhospital staff, e.g. machine technicians, all add to the costs of thesurgical procedure.

Recognition of the disadvantages and risks of open heart surgery hasrecently led to attempts at minimally invasive approaches. For example,smaller chest incisions, such as partial sternotomies or creating a“window” between adjacent ribs, are now being utilized in some instancesto access the aorta for performing certain heart bypass procedures.However, these approaches still require cracking and/or retracting ribsand are surgically difficult not only due to the limited access andmaneuverability of the instrumentation, but due to limited visibility.Additionally, the heart may need to be manipulated to provide properaccess, potentially causing additional trauma. For these reasons, suchminimally invasive approaches have found only limited applications inbypass procedures and to the inventors' knowledge have not beensuccessfully used for aortic valve replacement surgery.

U.S. Pat. No. 5,571,215 discloses another approach to avoiding theaforementioned problems and risks associated with a full sternotomy,i.e. open heart surgery. In the '215 patent, a percutaneous endoscopicmethod for valve installation is disclosed. Basically a series ofcannulas or trocars are inserted percutaneously, along with anendoscopic viewing device, and the valve replacement is performedthrough these small tubes with visualization on a remote video screen.To the inventors' knowledge, this form of endoscopic surgery is notcurrently being utilized, most likely because 1) access is limited; 2)the ability to manipulate the tissue and valve through small tubes isdifficult; 3) visibility is limited; 4) and the small instrumentationneeded for the procedure is limited. The problem with this endoscopicapproach is compounded by the fact that the valve is sutured to thevalve annulus. As can be appreciated, manipulating a suturing instrumentthrough small tubes, with limited maneuverability and restrictedvisibility is quite difficult. Additionally, as with suturing in openprocedures, the success of the suturing and knot tying can oftentimes bedependent on the particular skills of the surgeon. This method alsorequires opening the aorta, and ensuring proper closure after thesurgery.

Therefore, to date, no surgical method is effective in avoiding theaforementioned disadvantages of open heart valve surgery. Thus, it wouldbe advantageous to provide a minimally invasive method to insert andimplant a heart valve, therefore avoiding the problems and risksassociated with open surgery. It would also be advantageous to provide areplacement valve that can more easily be secured to the valve annuluswithout requiring the difficult, skill dependent and time consumingsuturing and knot tying of the replacement valve.

SUMMARY

The present invention overcomes the disadvantages and deficiencies ofthe prior valves and valve insertion methods. The present inventionprovides a valve configured for insertion on the proximal and distalsides of a heart valve annulus to replace the heart valve of a patient.The valve comprises a first substantially annular portion adapted to bepositioned on a proximal side of the annulus and a second substantiallyannular portion adapted to be positioned on a distal side of theannulus, wherein at least one of the first and second substantiallyannular portions is movable towards the other portion to a clampedposition to clamp around the annulus. The second substantially annularportion has a flow restricting portion extending therefrom and ismovable between a first position to permit the flow of blood and asecond position to restrict the flow of blood.

The first and second portions are preferably comprised of shape memoryalloy. In one embodiment, the valve has a suture joining the first andsecond substantially annular portions to draw them into closer proximityand a cinch member securing the suture to maintain the first and secondportions in the clamped position. In another embodiment, the first andsecond portions are formed from a unitary wire and are connected by awire segment which biases the first and second portions toward theclamped position. In this embodiment, the first substantially annularportion preferably underlies a first arcuate portion and a secondarcuate portion preferably underlies the second substantially annularportion to form a coiled wire of multiple overlapping segments.

Various embodiments of flow restricting portions are provided. In oneembodiment, the flow restricting portion comprises a plurality ofleaflets extending circumferentially around the second portion in adirection away from the first portion and are foldable inwardly towardsa convergence region at the midpoint of the second portion so theconvergence region is concentric with the second portion to restrictblood flow. In another embodiment, the leaflets are foldable inwardlytowards a convergence region offset from a midpoint of the secondportion so the convergence region is eccentric with the second portionto restrict blood flow. The flow restricting portion may further includea membrane joining adjacent leaflets to cooperate with the leaflets torestrict blood flow when the leaflets are in the closed position.

A replacement cardiac valve implantation system is also providedcomprising a valve and a delivery member. The valve comprises a wireelement having a first ring-like portion and a second ring-like portionpositioned over the first ring like portion. At least the first ringlike portion is movable towards and away from the second ring-likeportion and is biased towards the second ring like portion. The deliverymember introduces the wire element into a patient's body, such that thefirst ring-like portion is placed on a first side of the annulus and thesecond ring-like portion is placed on a second side of the annulus, thebias of the portions forcing the first ring-like portion in closerproximity to the second ring-like portion to secure the valve in aclamped position around the annulus. The first and second ring-likeportions are preferably joined by an arcuate wire segment extendingtherebetween which biases the first and second ring-like portions to aclamped position.

A method of installing a valve to replace a heart valve of a patient isalso provided comprising:

positioning a valve in a first configuration inside a first catheter;

inserting the first catheter through the femoral artery;

advancing the first catheter around the aortic arch so that a distal endportion of the first catheter is adjacent an annulus of a patient;

ejecting a first portion of the valve from the first catheter toposition it on a first side of the annulus; and

ejecting a second portion of the valve from the first catheter on asecond side of the annulus allowing the first and second portions of thevalve to clamp around both sides of the annulus.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiment(s) of the present invention are described hereinwith reference to the drawings wherein:

FIG. 1A is an isometric view showing the delivery catheter beinginserted percutaneously though the left femoral artery to access theaortic valve annulus;

FIG. 1B is an enlarged perspective view of the proximal portion of thedelivery catheter shown inserted into a conventional sheath;

FIG. 2A is a broken view of a percutaneously inserted valve resectorshown extending through the delivery catheter and around the aortic archto minimally invasively resect the aortic valve, and further showing theresected tissue being suctioned from the delivery catheter;

FIG. 2B illustrates the resector of FIG. 2A withdrawn into the deliverycatheter, proximal of the slit valve, with the resected tissue beingsuctioned through the catheter;

FIG. 3 is a broken view of a percutaneously inserted rongeur shownextending around the aortic arch and protruding through the deliverycatheter to minimally invasively resect the aortic valve;

FIG. 4 is a perspective view of the rongeur of FIG. 3 with a portion ofthe delivery catheter removed to show the resected tissue beingsuctioned through the rongeur;

FIG. 5 is a perspective view of the valve annulus of the patient;

FIG. 6-9 illustrate the steps of insertion of the valve of a firstembodiment of the present invention wherein

FIG. 6 is a perspective view showing the partial ejection of the firstwire element from the delivery catheter to a position on the proximalside of the annulus;

FIG. 7A is a perspective view showing the first wire element furtherejected from the catheter for deployment on the proximal side of theannulus to form a first or proximal ring;

FIG. 7B is a perspective view showing the first ring fully ejected fromthe valve retaining catheter (the delivery catheter removed for clarity)and with the catheter sectioned to illustrate the positioning of thesecond wire element and suture cinch mechanisms therewithin;

FIG. 8 is perspective view showing full deployment of the first andsecond wire elements to form the first and second rings positioned onthe proximal and distal sides of the annulus, respectively, and showinga first embodiment of the valve leaflets in the open position (withseveral of the leaflets removed for clarity);

FIG. 9 is a perspective view of the delivery catheter and a sectionalview of the first and second rings fully deployed and the suture beingtightened to clamp the rings on the annulus;

FIG. 10A is a partial cross-sectional view illustrating the valve ofFIGS. 6-9 in the clamped position around the annulus with the cinchmechanism in the locking position;

FIG. 10B is a perspective view of the valve of FIGS. 6-9 in the clampedposition with the leaflets in the open position to allow blood flow inthe direction of the arrow;

FIG. 10C is a perspective view of the valve of FIGS. 6-9 in its clampedposition with the leaflets in the closed position to stanch blood flow;

FIG. 11A is a perspective view of the cinch mechanism of FIG. 10A forretaining the suture with part of the housing removed for clarity;

FIG. 11B is a perspective view showing the cinch mechanism of FIG. 11Aattached to a top surface of the distal ring;

FIG. 12A is a perspective view of a second embodiment of the valve ofthe present invention;

FIG. 12B is a perspective view showing initial deployment of the valveof FIG. 12A from a delivery catheter to form a first (proximal) ring;

FIG. 13 is a perspective view showing the valve of FIG. 12 clamped onthe annulus with a second embodiment of the leaflets in the openposition to allow blood flow;

FIG. 14 is a perspective view showing the valve of FIG. 13 clamped onthe annulus with the leaflets in the closed position to stanch bloodflow;

FIG. 15 is a side view of a third embodiment of the valve leaflets in aclosed position shown having a curved overlapping configuration;

FIG. 16 is a top view of the valve of FIG. 15 showing the overlappingleaflets in a closed configuration, concentric with the ring, torestrict blood flow;

FIG. 17 is a side perspective view of the valve leaflets of FIG. 15 inthe open position showing the membrane joining adjacent leaflets;

FIG. 18 is a perspective view showing the valve of FIG. 12, with theleaflet configuration of FIGS. 15-17, in the closed position and clampedon the annulus;

FIG. 19 is a side view of the valve of FIGS. 6-9, with the leafletconfiguration of FIGS. 15-17, shown clamped on the annulus and in theopen configuration, with only a few of the leaflets shown for clarity;

FIG. 20 is a bottom view of a fourth embodiment of the valve leaflets ofthe present invention;

FIG. 21 is a top view of the valve leaflets of FIG. 20 shown in a closedposition eccentric with the second (distal) ring;

FIG. 22 is a side view of the valve of FIG. 20 showing the eccentricleaflets in the closed position;

FIG. 23 is a perspective view of a fifth embodiment of the valveleaflets of the present invention, having a membrane joining adjacentleaflets, shown in the closed position;

FIG. 24 is a side view of the valve of FIG. 23 shown in the closedposition;

FIG. 25 is a top view of the valve of FIG. 23 shown in the closedposition;

FIG. 26 is a cross sectional view taken along lines 26-26 of FIG. 23showing the varying thickness of the valve leaflets and membrane;

FIG. 27 is a perspective view of a sixth embodiment of the valveleaflets of the present invention shown in the open position to allowblood flow;

FIG. 28 is a top view of the valve of FIG. 27 showing the leaflets inthe closed position to restrict blood flow;

FIG. 29 is a cross-sectional view taken along lines 29-29 of FIG. 27showing the leaflets threaded onto the second (distal) ring;

FIG. 30 is a cross-sectional view of an alternate way to attach theleaflets showing the leaflets attached to the upper surface of thesecond ring;

FIG. 31 is a perspective view of an alternate approach to inserting thevalve of the present invention; and

FIG. 32 is a perspective view of another alternate approach to insertingthe valve of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring now in detail to the drawings where like reference numeralsidentify similar or like components throughout the several views, FIGS.6-10 illustrate a first embodiment of the heart valve of the presentinvention and FIGS. 12-14 illustrate a second embodiment of the heartvalve of the present invention, each valve configured and dimensionedfor minimally invasive insertion and implantation in a patient's body.Various leaflet embodiments for use with either valve are disclosed inFIGS. 15-30 and described in detail below.

The valve of the present invention, designed to replace the patient'saortic valve, is contained within a valve retaining catheter andinserted through a delivery catheter 70 as shown in FIGS. 1A and 1B.Delivery catheter 70 is retained within a conventional sheath 101 havinga side arm or tube 109 for flushing the surgical site. Sheath 101 has aslit valve 103 to seal around the delivery catheter 70 when insertedtherethrough. Delivery catheter is inserted through the femoral artery“a” in the patient's leg, directed through the aortic arch “b” and intothe left ventricle “c” of the patient. The valve is then deployed aroundthe annulus, (a naturally formed tissue collar) in the manner describedbelow to thereby form a replacement prosthetic valve to provide thefunction of the aortic valve. It should be understood that although thevarious embodiments of valves of the present invention are describedbelow for replacement of the aortic valve, the valves of the presentinvention could also be used to replace other valves such as the mitralvalve.

The valve of the present invention, as can be appreciated, is insertedintraluminally (or percutaneously through the femoral artery) so theaorta does not need to be penetrated to provide access to the annulus.To complement the intraluminal implantation of the valve,instrumentation is provided to resect the natural valve of the patientintraluminally. Thus, by providing a percutaneous valve resector, anentire percutaneous system is provided since the resection of thenatural valve as well as insertion and implantation of the replacementvalve can be achieved percutaneously, e.g. through a small incision intothe femoral artery in the patient's leg. The intraluminal insertionavoids a sternotomy or partial sternotomy and its associated risks anddisadvantages discussed above. FIGS. 2-5 illustrate two examples ofinstrumentation to percutaneously (intraluminally) remove the defectiveaortic valve.

Turning first to FIGS. 2A and 2B, a first embodiment of a valveresecting instrument is designated by reference numeral 50. Resectinginstrument 50 is inserted through delivery catheter 70. Deliverycatheter 70 is inserted through a small incision in the patient's leg toaccess the femoral artery (not shown), retained within sheath 101 (seeFIG. 1), and advanced through the femoral artery and around the aorticarch “b” to access the patient's defective valve. Delivery catheter 70has slit valves 72, 74 on its proximal and distal ends 76,78,respectively, to maintain a fluid seal when surgical instruments areinserted into the lumen 77 of the delivery catheter 70. Thus, blood anddebris are prevented from entering into the lumen 77 except for removalof resected valve tissue as described below. Delivery catheter 70 has aside tube or arm 79 connected to a suction source to remove the resectedvalve tissue.

Resecting instrument 50 has a flexible outer tube 58, a pair ofresecting jaws 56 extending from a distal end 55 of the outer tube 58,and a jaw manipulator such as a wire (not shown) mechanically connectedto the jaws 56 to manipulate the jaws 56 between open and closedpositions to resect the valve. Resecting jaws 56 of resecting instrument50 are controlled from a proximal end of outer tube 58, which extendsproximally of slit valve 72 to provide access to the surgeon outside thepatient's body. Thus, the wire or controller is manipulated from outsidethe body to resect the valve. The resected valve tissue is suctionedthrough the slit valve 74 (the negative pressure opening the valve 74)and through delivery catheter lumen 77, in the space between inner wall73 of delivery catheter 70 and outer wall 53 of resecting instrument 50,as shown in FIG. 2B. Alternatively, a separate suctioning instrument canbe placed alongside the resecting instrument 50 within the deliverycatheter 70. The pressure of the blood from the aorta can aid in pushingthe debris out through the valve 74.

An alternate embodiment of the valve resector is shown in FIGS. 3 and 4.A flexible rongeur 60 is depicted having a central lumen 62 to suctionthe resected pieces of the valve therethrough. FIG. 4 illustrates adistal end portion 64 of the rongeur 60, with a portion of deliverycatheter 70 removed, to show the tissue being removed through the lumen62. The rongeur 60 is inserted through the delivery catheter 70 in thesame manner as the aforedescribed resecting instrument 50. To resecttissue, the tissue is placed between end plate 64 and cutter 66. Plate64 is retracted in the direction of the arrow, or alternately the cutter66 is advanced toward the plate 64, thereby forcing the tissue againstcutter 66 for resecting the valve. The resected tissue is suctionedthrough lumen 62.

FIG. 5 illustrates the patient's anatomy with the aortic valve removedto enable implantation of a replacement valve. The annulus is designatedby letter “n” and due to its annular collar like configuration, providesa natural mount or clamping surface for the valve of the presentinvention which will become apparent from the discussion below.

Turning now to the first embodiment of the valve illustrated in FIGS.6-9, and referring first to FIG. 8, the valve 10 includes a first wireforming a first or proximal ring 14 and a second separate wire forming asecond or distal ring 12. The first and second wire rings 14, 12 arejoined by a series of sutures 24. Although three sutures 24 are shown,additional or fewer sutures can be utilized. The wire can alternativelybe composed of a unitary element so that the proximal and distal ringsform a unitary piece joined by a wire portion therebetween. The wire canbe made of stainless steel, but is preferably composed of shape memorymaterial such as Nitinol (nickel-titanium alloy). Shape memory alloyenables the wires to be retained inside the valve retaining catheter 11in an elongated position, extending along the longitudinal axis of thecatheter 11 as shown in FIG. 7B, and return to a preconfigured,memorized configuration when deployed from the catheter. Consequently,the proximal and distal rings can be positioned in the catheter, onebehind the other or even adjacent each other in a substantially straightposition, thereby allowing a small diameter delivery catheter to beutilized. This is best illustrated in FIG. 7B which illustrates thedistal ring 14 deployed from the valve retaining catheter 11 but theproximal ring 12 still retained in its straightened configuration insidethe catheter 11. Note that both the distal and proximal wire rings 14 12have atraumatic tips, such as a ball tip 17, 19, respectively, at theirexposed ends.

A pusher (not shown) ejects the first or proximal wire ring 14 bycontact with a proximal end, enabling it to return to its substantiallyannular configuration. After ejection of the first ring 14, either thesame pusher, or a separate pusher proximal to or alongside the firstpusher, ejects the distal wire ring 12 by advancing it from its proximalend, allowing it also to return to its substantially annularconfiguration. The sutures 24 which wrap around and hold the ringstogether, are ejected as the rings 12, 14 are ejected.

Three sutures 24 are provided, preferably about 120 degrees apart asshown. Each suture is wrapped around the rings 12 and 14 as best shownin FIGS. 7B, 9 and 11B, and are tensioned to draw the rings 12 and 14toward each other. A cinch mechanism 26 comprising a housing 27 andpivotable locking element 28 (see FIG. 11A) is provided for each suture.Housing 27 has a convex surface 25 to conform to an outer surface of thedistal ring 12 to enable it to rest atop ring 12 and is preferablywelded or adhesively attached thereto. Alternatively, housing 27 can beprovided with a longitudinally extending opening to receive the distalwire therethrough.

One end 24 a of each suture 24 is secured within slot 21 and the otherend 24 b is retained between locking element 28 and inner wall surface23. End 24 b, prior to being cut, extends beyond the length of thecatheter, exiting through the proximal end. The suture is tensioned bypulling from its proximal end, thereby moving the two rings 12, 14towards each other into locking engagement. Locking element 28, springbiased as shown, prevents movement of the suture in a distal directionto maintain the suture and respective rings in a clamped (locked)position.

A series of leaflets or petals 30 extend upwardly from the distal ring12 along the entire circumference as seen in FIGS. 8 and 10B. (Only someof the leaflets are shown in FIG. 8 for clarity.) Leaflets 30 arepreferably attached to distal ring 12 by welding or adhesives; however,other methods of attachment as known in the art can also be utilized.Leaflets 30 are movable from an open position as shown in FIG. 10B toallow blood flow from the heart to the aorta to a closed position shownin FIG. 10C, where their end portions are curved and converge to aclosed position to prevent blood flow. The point of convergence as shownis aligned with a center region of the rings 12, 14.

The steps of deploying and securing the valve 10 will now be described.First, the delivery catheter 70 is inserted through a conventionalsheath, over a conventional guidewire (not shown) through the femoralartery, around the aortic arch, and down to the aortic valve areaadjacent the valve annulus (the aortic valve having already beenremoved). As shown in FIG. 6 the distal end 76 of the delivery catheter70 is placed slightly past of the valve annulus, i.e. on the “inner”side of the annulus, also referred to herein as the proximal side of theannulus, relative to the heart. The guidewire is then removed. Valveretaining catheter or valve sheath 11, with the aortic valve 10contained therein in an elongated orientation, with the leaflets folded,is inserted through the delivery catheter 70 and likewise advancedthrough the femoral artery, around the aortic arch to adjacent the valveannulus.

The first wire element, which will form the first or proximal (inner)ring 14, is initially advanced from the valve retaining catheter 11 andthrough the slit valve 74 of the delivery catheter 70 to the position ofFIG. 6, ensuring it is on the proximal side of the annulus “n”, relativeto the heart. FIG. 7A illustrates further advancement of the first wireelement to enable it to return to its memorized configuration to formproximal annular ring 14 (see also FIG. 7B). After deployment of thering 14, the second wire element is ejected from valve retainingcatheter 11 through slit valve 74 of delivery catheter 70, allowing itto return from its straightened configuration within the valve retainingcatheter 11 to its memorized configuration, shaped to form an annularsecond ring 12 on the distal (outer) side of the annulus, as shown inFIG. 8. The sutures are wrapped around the rings 12 and 14 as shown,with housing 27 of cinch mechanism 26 attached to the second ring 12 sothe sutures are ejected with the rings 12, 14.

Once the wire elements are fully deployed and the positioning of thefirst and second rings 14, 12 on respective sides of the annulus isconfirmed by visualization techniques such as ultrasound, the rings 14,12 are pulled together by tensioning the suture 24. The surgeon manuallypulls on the proximal end of each suture which extends proximally of thedelivery catheter 70 and valve retaining catheter 11 outside the body.The two rings 12, 14 are thus pulled tightly together to clamp aroundthe annulus with the cinch mechanism 26 ensuring that the suture issecured to lock the rings in this clamped position. The excess suture iscut at proximal end 24 b and the valve retaining catheter 11 anddelivery catheter 70 are withdrawn, leaving the valve 10 secured aroundthe annulus. As noted above, although described for aortic valvereplacement, the valve 10 described herein can be used to replace othervalves such as the mitral valve. It should also be noted in FIG. 9, thecinch mechanism 26′ is shown spaced from the distal ring 12, it beingcontemplated that the cinch mechanism can alternatively be slid intoengagement with the distal ring 12 by a pusher (not shown), and attachedthereto by conventional means such as a snap fit.

An alternate (second) embodiment of the valve of the present inventionis illustrated in FIGS. 12-14 and designated generally by referencenumeral 40. Valve 40 includes a coiled wire element preferable ofunitary construction which forms a first or proximal (inner) ring 42 anda second or distal (outer) ring 44. The rings 42 and 44 are joined by anarcuate wire segment 45 which also functions to bias the rings 42 and 44toward each other as discussed below.

As shown, the first ring 42 has a 360 degree segment 46 which extendsinto overlying partially annular or arcuate segment 48, preferablyranging from about 90 to about 180 degrees. Second ring 44 likewise hasa 360 degree segment 47 extending into underlying partially annular orarcuate segment 49, preferably ranging from about 90 to about 180degrees. Thus, in the illustrated embodiment each ring 42, 44 can beconsidered to circumscribe at least about a 450 degree segment forming acoiled wire of multiple overlapping segments. Arcuate segment 48transitions into arcuate segment 49 in the transition area defined bywire segment 45 extending at an angle to the parallel planes defined byeach of the rings 42, 44.

A series of substantially triangular leaflets 50 extend from the secondring 44, preferably attached thereto by adhesive, although other meansof attachment are also contemplated. When in the closed position of FIG.14, leaflets 50 converge at a concentric point 52, aligned with themidpoint of rings 42, 44 to close off blood flow. As in the valve of thefirst embodiment, the rings 42, 44 are placed on opposing sides of theannulus, i.e. on proximal and distal sides of the annulus relative tothe heart. The bias of wire segment 45 forces the rings 42, 44 togetherto clamp against the annulus.

The wire element is preferably composed of a shape memory material, suchas Nitinol, having the memorized configuration of FIG. 12A. Thus, thewire element is contained in the valve retaining catheter or valvesheath 13 in a longitudinally straightened position, with the leafletsfolded, to reduce the profile for insertion. In use, delivery catheter70 is inserted into a conventional sheath (e.g. sheath 101 of FIG. 1A)and advanced over a guidewire through the femoral artery as describedabove with the distal end of the delivery catheter 70 placed on the“inner” or proximal side of the annulus. Next, valve retaining catheter13 with the wire element contained therein is inserted through the slitvalve 72 of the delivery catheter 70 and advanced around the aortic archto terminate adjacent the distal end of delivery catheter 70. A pusherelement pushes the wire element distally outside the valve retainingcatheter 13 and delivery catheter 70. FIG. 12B illustrates wire elementinitially advanced. (Note that FIG. 12B shows the leaflets 50 in theunfolded condition for clarity, it being understood that the leafletswould be folded or compressed within the valve retaining catheter 13 toreduce the profile).

When the wire element is deployed, the first ring segment reverts fromit straightened configuration inside the valve retaining catheter 13 tothe memory configuration of FIG. 12B, thus forming a first (proximal)ring 42 with an overlying segment 48. Once the position of the proximalring 42 is confirmed using applicable visualization techniques, the wireelement is further deployed, allowing the second wire to return to itsmemory configuration to form a second or distal ring 44 with underlyingsegment 49. The rings 42, 44 are then forced together by wire segment 45to the position of FIG. 14, with the rings 42,44 clamped on opposingsides of the annulus. Thus, sutureless attachment to the annulus isachieved.

FIG. 14 illustrates the valve leaflets 50 in the closed position, wherethey converge at their tips during diastole. Their systolic or openposition is illustrated in FIG. 13. It should be appreciated that therounded edge, curved leaflets of the embodiment of FIG. 8 couldalternatively be used with the valve of the second embodiment of FIG.12-14.

Various alternate embodiments of valve leaflets are disclosed in FIG.15-30 and will now be described. The leaflets need to accommodate twocompeting requirements: long term stability to handle repeated openingand closing without inverting or undesirably contacting the vessel walland flexibility for unimpeded opening and closing to simulate naturalvalve function. The embodiments described below are intended to strike abalance between these two requirements. It should be understood thatthese leaflet configurations could be used with either of the two valveembodiments 10, 40 described above. Additionally the leaflets can beattached to the surface of the distal ring by welding, adhesive, insertmolding or other means. Alternatively, the distal ring can extenddirectly through the leaflets to secure the leaflets to the ring.

Turning first to FIGS. 15-18, in this embodiment, leaflets 80, havingrounded edges 81, are connected by a membrane 82 of sheet material. Themembrane 82 will add to the stability of the leaflets by reducing thelikelihood of inversion or “floppy valve” and may minimize post stenoticvalve fibrillation or beating/trauma against the aortic wall. Theleaflets 80, when closed, converge in a partially overlapping fashion toa midpoint “M” concentric with the distal and proximal rings, i.e.aligned with the centerline of the rings. The curved or spiral-likeoverlapping configuration will also add to the stability of the leafletsand reduce the likelihood of leakage. FIG. 18 illustrates the leaflets80 utilized with the embodiment of FIGS. 12-14 and FIG. 19 illustratesthe leaflets 80 utilized with the embodiment of FIGS. 6-10.

In the embodiment of FIG. 20-22, the leaflets 90 are curved and alsohave a membrane 92 joining adjacent leaflets. However, the leaflets 90,when closed into their curved partially overlapping configurationconverge to a point “E” eccentric with respect to the distal andproximal rings. Thus, the convergence point “E” of the leaflets 90 isoffset with respect to the centerline of the rings. This offset willdirect blood flow toward the side of the vessel rather than in thecenter of the vessel as in the concentric leaflets of FIGS. 15-17.

FIGS. 23-25 illustrate another embodiment of leaflets of the presentinvention. Leaflets 100 are connected by a membrane 102 to increase thestability of the leaflets. The membrane 102 joins adjacent leaflets,however, alternatively, the membrane can extend around the entireperiphery of the leaflets, functioning to further prevent leakage whenthe valve is closed. As shown in the cross sectional view of FIG. 26,the leaflets 100 have a thickness greater than the thickness of themembrane 102. This will increase stability towards the base of theleaflets, i.e. closer to the distal ring 44, while increasingflexibility towards the top or outer portion of the leaflets. In theclosed position, the leaflets 11 converge at point “F”, aligned with thecenter point of the rings.

The foregoing membranes can be composed of polyethylene, PTFE, or othersuitable materials. Additionally, flexible metallic struts, made frommaterials such as Nitinol, can also be embedded in the membrane 82 toprovide additional support.

A porcine or tricuspid valve is illustrated in FIGS. 27-30. This valveconfiguration more closely resembles the natural valve of the patient.In this embodiment, the tricuspid valve 110 having three leaflets 112can be connected to the top of distal ring 44 as shown in FIG. 29.

FIG. 30 illustrates an alternative way to attach the leaflet. In thisversion, the ring 44 extends directly through the leaflets 200, e.g. theleaflets are threaded onto the wire ring.

Alternate Approaches

As discussed above, the valves of the present invention are designed forpercutaneous (intraluminal) insertion through the femoral artery.However, the inventors have realized that some surgeons might prefereither a full or partial sternotomy before transitioning to a minimallyinvasive approach. Some surgeons may also prefer the “window” approachwhich involves an incision between, and retraction of, the ribs of apatient. The valves of the present invention provide an advantage evenif performing a sternotomy or “window” approach since they avoid thetime consuming and complicated steps of suturing the valve to theannulus. FIG. 31 illustrates how either valve of the present inventioncan be inserted through the aorta, in an open or more invasive surgicalprocedure. A portion of the aortic wall would be dissected as shown, anda delivery catheter 200 containing a valve retaining catheter 210 wouldbe inserted therethrough. The valve 10 or 40 would be deployed from thevalve retaining catheter 210 in the manner described above, and clampagainst the annulus to provide sutureless attachment to the annulus asdescribed above.

Although the endoscopic approach has not been clinically accepted forreasons suggested above, in the event this approach becomes accepted,the valve 10 and 40 of the present invention would provide an advantagebecause of their sutureless attachment to the annulus. FIG. 32illustrates such insertion of the valve through an endoscope 300 in athoracoscopic approach to valve replacement.

While the above description contains many specifics, those specificsshould not be construed as limitations on the scope of the disclosure,but merely as exemplifications of preferred embodiments thereof. Thoseskilled in the art will envision many other possible variations that arewithin the scope and spirit of the disclosure as defined by the claimsappended hereto.

1. A valve configured for minimally invasive insertion on the proximaland distal sides of a heart valve annulus to replace the heart valve ofa patient, the valve comprising: a first substantially annular portionadapted to be positioned on a first side of the annulus of a patient; asecond substantially annular portion adapted to be positioned on asecond side of the annulus of a patient, at least one of the first andsecond substantially annular portions being movable towards the otherportion to a clamped position to clamp around the annulus, the first andsecond substantially annular portions contained in an elongated reducedprofile condition in a delivery position, the second substantiallyannular portion having a movable flow restricting portion extendingtherefrom, the flow restricting portion including a plurality ofleaflets extending from the second portion in a direction away from thefirst portion, the leaflets extending circumferentially around thesecond portion and foldable inwardly towards a convergence region torestrict blood flow and movable outwardly to an open position to permitblood flow, the leaflets compressible to a reduced profile condition ina delivery position.
 2. The valve of claim 1, wherein the leaflets arefoldable inwardly towards a convergence region at the midpoint of thesecond portion so the convergence region is concentric with a centerlineof the second portion to restrict blood flow.
 3. The valve of claim 1,wherein the leaflets are foldable inwardly towards a convergence regionoffset from a midpoint of the second portion so the convergence regionis eccentric with a centerline of the second portion to restrict bloodflow.
 4. The valve of claim 1, wherein end portions of the leaflets arecurved.
 5. The valve of claim 1, wherein the leaflets converge in apartially overlapping spiral like configuration.
 6. The valve of claim1, wherein the plurality of leaflets comprises three leaflets forming atricuspid valve.
 7. The valve of claim 1, wherein at least a portion ofthe first and second portions lie in parallel planes.
 8. The valve ofclaim 1, wherein the flow restricting portion further includes amembrane joining adjacent leaflets to cooperate with the leaflets torestrict blood flow when the leaflets are in the closed position.
 9. Thevalve of claim 8, wherein the membrane extends around the entireperiphery of the leaflets.
 10. The valve of claim 8, wherein theleaflets have a thicker portion at a portion closer to the secondportion and the membrane has a thinner portion at a portion further fromthe second portion.
 11. The valve of claim 8, further comprisingmetallic struts embedded in the membrane.
 12. The valve of claim 2,wherein the flow restricting portion further includes a membrane joiningadjacent leaflets to cooperate with the leaflets to restrict blood flowwhen the leaflets are in the closed position.
 13. The valve of claim 3,wherein the flow restricting portion further includes a membrane joiningadjacent leaflets to cooperate with the leaflets to restrict blood flowwhen the leaflets are in the closed position.
 14. The valve of claim 1,wherein adjacent leaflets overlap in the closed position to restrictblood flow.
 15. The valve of claim 1, wherein the leaflets aresubstantially triangular in configuration.